Republicans risk too much in the shutdown battle, because it’s being fought mainly in the media.

Cannon to the right of them,Cannon to the left of them, . . . Into the jaws of Death,Into the mouth of Hell Rode the six hundred.

— Alfred, Lord Tennyson, “The Charge of the Light Brigade”

Almost exactly 159 years ago, a British light-cavalry brigade rode directly into Russian guns at the battle of Balaclava in the Crimean War. Tennyson was available to immortalize the valor of the soldiers who rode bravely to their deaths (“theirs was not to reason why”). How stirring, for the survivors.

The light brigade was actually meant to harry a retreating Russian artillery battery. But “someone had blundered” and the order was given that the six hundred ride directly into a valley surrounded by Russian guns.

Good generals are responsible for choosing their battles wisely. In politics, as in war, the goal should be victory, not glorious (or “principled”) defeat.

The Republicans’ blunder is to risk so much in a short-term public-relations battle fought mainly through a medium that Democrats control — the press. With a few exceptions, the American press is the Democrats’ artillery in any battle with Republicans.

You may say, in that case, why should Republicans ever take on the Democrats? Won’t the press always create a hopelessly uneven playing field?

Yes, but a shutdown showdown is almost uniquely sensitive to short-term public perceptions. Each side stakes out its position and then waits for public pressure to force the other to blink.

Mark Halperin of Time magazine offered a frank assessment of the Obama team’s calculation: “Here what’s the White House and to some extent the Hill is going to monitor. One is how the press covers the shutdown and does it just go back into the ’90s mode of saying ‘obstructionist Republicans are causing a shutdown and people, real people are hurting?’ And the White House is assuming that’s going to happen.”

Good assumption. The Media Research Center analyzed the coverage of the big three TV networks in the two weeks prior to the shutdown. Of 25 stories that assigned blame for the government closure, 21 blamed Republicans and the “crazed” tea-party wing, and four blamed both parties. CBS’s Bob Schieffer explained to viewers that the crisis was provoked by “ultra-conservatives. . . . We’re headed to a shutdown unless the moderates in the House revolt.”

It takes two to produce an impasse, right? Not according to the almost unanimous press refrain. The Washington Post editorialized that the government shutdown was endangering national security — 72 percent of the civilian intelligence-agency personnel have been furloughed, according to Senator Dianne Feinstein. But it doesn’t even occur to the Post’s editorial board to hold both parties to account for this: “Republicans are putting U.S. embassies across the world at risk with their shutdown of the U.S. government. More broadly, they are endangering national security at a time when the United States remains under threat from al-Qaeda and affiliated groups” (my emphasis).

House Republicans have passed measures to keep funds flowing to the District of Columbia, the National Park Service, and the National Institutes of Health, but Senate Democrats declined to vote on these. Is this a big story? No. Harry Reid was even caught in the kind of gaffe that would be a career-ender for a Republican. CNN’s Dana Bash framed the NIH funding question this way: “If you can help one child who has cancer, why wouldn’t you do it?” Reid replied, “Why would we want to do that?”

It would be unfair to conclude from that slip of the tongue that Harry Reid is indifferent to the welfare of children with cancer. Fair-minded people can agree on that. Can we also agree that if a Republican had said it, it would be featured in a constant loop on TV and elsewhere? Is there any doubt that if the roles were reversed, Democrats would be marching children with cancer before cameras to plead with Republicans to restore funding, and the press would be reporting that Republicans want children to die?

Barack Obama is the first president in living memory who has attempted to spook the financial markets in a transparent attempt to win a partisan advantage. He is also the first in recent memory flatly to decline to negotiate with the other party. When he invited congressional leaders to the White House on Wednesday evening, his spokesman, Jay Carney, was careful to explain that “there was nothing to negotiate.”

This is the battle Obama wanted because his cannons are arrayed on the high ground, controlled by his press.